Air-cushion vehicles

ABSTRACT

In a tracked air cushion vehicle system, the vehicle is supported and/or guided by one or more air cushions formed in a chamber between a wall of the track and a support of guidance platform, the enclosure of the chamber being completed by walls or bogies linked to the platform but movable independent of it, at least in a direction towards and away from the track without having to move with the platform and thus bear loads imposed by it. Both pendulum and non-pendulum forms of suspension are described, and the preferred embodiments of the invention utilize air cushions operating at subatmospheric pressures.

United States Patent 1191 Bliss Mar. 19, 1974 1 AIR-CUSHION VEHICLES [75] Inventor: Denys Stanley Bliss, Cambridge,

England [73] Assignee: Bliss Pendair Limited, London,

England [22] Filed: May 5, 1971 21] Appl, No.: 140,478

[30] Foreign Application Priority Data May 7. 1970 Great Britain 22078/70 [52] US. Cl 104/23 FS, 104/134 [51] Int. Cl. B61b 13/08 [58] Field of Search 104/23 FS, 134; 180/115,

3,381,627 5/1968 Hart 104/23 FS 3,511.186 5/1970 Barthalon 104/23 FS 3.515.073 6/1970 Faure 104/23 FS Primary Examiner-Gerald M. Forlenza Assistant Examiner-D. W. Keen Attorney, Agent, or Firm--Baldwir1, Wight & Brown [57] ABSTRACT a direction towards and away from the track without having to move with the platform and thus bear loads imposed by it. Both pendulum and non-pendulum forms of suspension are described, and the preferred [56] References Cited 1 UNITED STATES PATENTS embodiments of the invention ut1l1ze air cushlons operating at subatmospheric pressures. 3.631.806 1/1972 Barthalon 104/23 FS 3.167.145 1/1965 Mackie 104/23 FS 33 Claims, 84 Drawing Figures A82 2 l\\\\\\\ \y\\ PATENTEDHAR-I 9 I974 sum 03 or 28 x E g \9 9 IR\\ PATENTEUMAR 19 I974 sum on or 28,

PATENTEDMAR 18 I974 sum as 0F 2a DOW/V PATENTEUHAR 19 I974 sum as or 28 PATENTEUHAR 19 1914 3797398 SHEET 0? OF 28 20 f 45 I32 /24 Q/46 H XYZ PATENTEDMAR 19 1974 I 3.791.398

SHEET 10 0F 28 5 D/RECT/O/V OF I MOVfMf/VT I I I l I I l PAIENTEDMA 1 m4 3.7971398 SHEET '13 0F 28- sum 16 0F 28 PATENTEDMAR 19 mm wmm 

1. An air cushion vehicle system including an elongated track of a channel section having a bight portion defining a vehicle sustaining surface, said system further including a vehicle having at least one air cushion means, said air cushion means comprising a first wall facing said surface and further walls at opposite ends of said first wall and cooperating with said first wall and with said channel to define a chamber, pressure control means on the vehicle communicating with said chamber to maintain therein a pressure different from the surrounding atmosphere whereby to apply a suspension force to said first wall which wall is associated with part of a load bearing portion of the vehicle wherein the first wall is guided by said further walls for movement relative both with respect to the sustaining surface and to said further walls at least in a direction towards and away from the sustaining surface, said further walls being located relative to said surface in said direction by interaction with the sustaining surface, and wherein the pressure within the chamber is controlled in response to movement of the first wall relative to the sustaining surface in said direction.
 2. A system according to claim 1, wherein the track is configured both to guide and support the vehicle.
 3. A system according to claim 2, wherein the track is inverted and said sustaining surface is the roof thereof.
 4. A system according to claim 3, wherein the first wall is an elongated support platform from which a load bearing body of said vehicle is suspended, the further walls are provided by end members selected from plates and bogies, said end members extending to the roof and side walls of the track and linked to the ends of the support platform, said end members being restrained against substantial transverse movement relative to the track.
 5. A system according to claim 4, wherein the vehicle is propelled by at least one linear induction motor mounted in cooperating relation with an end member.
 6. A system according to claim 4, wherein the connection to the end members is such as to allow both motion of the platform relative thereto in a vertical direction and tilting movement of the platform about a longitudinal roll axis thereof.
 7. A system according to claim 6, characterized in that the platform is of predetermined width, and the side walls of the track have a cross-sectional profile selected to provide a predetermined relationship between the location of the platform within the track and the width of the gaps between the platform and the side walls.
 8. A system according to claim 7, characterized in that the platform is provided with flexible longitudinal edge portions.
 9. A system according to claim 8, characterized in that the platform is provided with nozzles extending along its longitudinal edge portions, and a fan supplying air under pressure to the nozzles, whereby to provide air curtains along either edge of the platform.
 10. A system according to claim 8, characterized in that the fan is operative to extract air from the chamber above the platform and recirculate it to the nozzles.
 11. A system according to claim 6 wherein in that the end members are each linked to the platform by a pin and slot arrangement, comprising a pin on the longitudinal roll axis of the platform, and a slot in the end member shaped to correspond to the locus of the said roll axis, the pin engaging the slot via means permitting movement of the platform relative to the track in a direction perpendicular to its plane.
 12. A system according to claim 6, wherein the platform is provided with conformable edge seals, cooperating with the side walls of the track, and means controlled by relative movement of the platform and the end members are provided to regulate the pressure within the chamber in dependence upon the relative positions of the platform and the end members.
 13. A system according to claim 12, wherein there is an air bleed aperture in a wall of the chamber provided with variable obturating means controlled by vertical movement of the platform.
 14. A system according to claim 13, characterized in that the shape of the air bleed aperture is selected to provide the platform with a predetermined vertical suspension characteristic.
 15. A system according to claim 13 wherein said pressure control means includes a fan for extracting air from said chamber, and said unobturated aperture is of a size permitting passage of sufficient air to prevent stalling of said fan.
 16. A system according to claim 13 wherein the air bleed aperture is defined by a plate arranged for vertical moveMent in guides in said end members, and said aperture defining plate is connected to the support platform by means operative to lower the aperture defining plate in response to inclination of the platform.
 17. A system according to claim 12, wherein the conformable edge seals comprise a flexible seal member received in a slot in the edge of the wall being sealed, and biased towards the track surface by biasing means.
 18. A system according to claim 17, wherein the biasing means is a chamber formed in the base of the slot and in communication with the atmosphere.
 19. A system according to claim 17, wherein the biasing means are springs.
 20. A system according to claim 17, including means directing pressurized fluid to the edges of the seal members adjacent to the track surface whereby to form fluid bearings.
 21. A system according to claim 20, wherein wheels are positioned to provide auxiliary location of the wall or plate being sealed.
 22. A system according to claim 6 wherein damping means are provided acting between the end members and the support platform.
 23. A system according to claim 6, wherein means acting on the track independently of the support platform are provided to control roll of the support platform.
 24. A system according to claim 6, wherein the platform is restrained against rolling movements by additional air cushion means connected to the platform and acting on the side wall of the track.
 25. A system according to claim 24, wherein the additional air cushion means comprise, on each side of the vehicle, a row of longitudinally spaced means defining air cushions, said air cushion means being connected to the platform by a system of levers allowing the row of air cushion means to conform to curvature of the track wall.
 26. A system according to claim 24, wherein the additional air cushion means comprise at least one further chamber defined on each side of the vehicle, by means of a central frame member supporting the platform, and seal plates slidable laterally relative to said frame member; said seal plates cooperating with said frame member, the end members and the side walls of the track to define said further chambers.
 27. A system according to claim 26, wherein the seal plates also form the edge portions of the platform and define the chamber above the platform.
 28. A system according to claim 26 wherein the position of the end members relative to the ends of the frame member determines the degree of obturation of passages placing the chambers defined above the platform and to either side of the frame member in communication with the atmosphere.
 29. A system according to claim 25, wherein the passages communicate with the atmosphere through at least one further chamber within the support platform, the support platform carrying suction fans having inlets in communication with the several chambers defined above and to either side of the frame member, and outlets in communication with said further chamber.
 30. A system according to claim 24, wherein the additional air cushion means comprise a separate guidance platform, the guidance platform cooperating with an additional vertically orientated channel section track portion to define an additional chamber, and wherein the additional track portion has top and bottom walls configured so that movement of the guidance platform, which is of fixed width, to either side of a predetermined lateral position results in gaps between the guidance platform and the top and bottom walls of the additional track portions becoming narrower, a fan unit being provided in communication with the additional chamber and adapted to selectively raise and lower the pressure therein relative to the atmosphere according to which side of said predetermined position the guidance platform lies.
 31. A system according to claim 30, wherein the guidance platform cooperates with a surface on the underside of both the top and the bottom walls of the additional track portion.
 32. A sysTem according to claim 26, wherein the seal plates have conformable edge seals.
 33. The system according to claim 32, wherein the conformable edge seals comprise a flexible seal member received in a slot in the edge of the wall being sealed, and biased towards the track surface by biasing means. 